eal: add macro to align value to the nearest multiple

[dpdk.git] / lib / librte_eal / common / include / rte_common.h

diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 7178ba1..bcf8afd 100644 (file)
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -248,6 +248,18 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
 #define RTE_ALIGN_MUL_FLOOR(v, mul) \
        ((v / ((typeof(v))(mul))) * (typeof(v))(mul))
 
+/**
+ * Macro to align value to the nearest multiple of the given value.
+ * The resultant value might be greater than or less than the first parameter
+ * whichever difference is the lowest.
+ */
+#define RTE_ALIGN_MUL_NEAR(v, mul)                             \
+       ({                                                      \
+               typeof(v) ceil = RTE_ALIGN_MUL_CEIL(v, mul);    \
+               typeof(v) floor = RTE_ALIGN_MUL_FLOOR(v, mul);  \
+               (ceil - v) > (v - floor) ? floor : ceil;        \
+       })
+
 /**
  * Checks if a pointer is aligned to a given power-of-two value
  *